25-31PC+ @20Hz -vs- 20-39PC+ @20hz output charts (1 Viewer)

[steve nn]

Hey' Thanks Frank. What is not in the pic is yet another opening just like the one on the right of the entrance. With one 25-31CS+ I can still hit 110 to 111db uncorrected on the SW II Fly-By scene. Basically a 30hz scene I think?

Ed could you explain all that again?

 

[Chris Grillo]

WOW,
I never new their was so much to this hobby! Ok I have downloaded all the stuff I need to get the charting of my sub and room done. now all I need is one more question answered so I don't blow my subs voice coil out!

Here we go "do I set the volume using my rat shack meter to 80-85db for plotting by using the 100Hz tone as the ref?? Or do I use the internal test tone of my rec. and my meter too set the base db volume too 80-85db.

Sorry i'm not sure how to begin :b
Thanks for being so patient!

PS my wife thinks I have gone crazy !

 

[Edward J M]

Use the 100 Hz test tone as a reference and set it to 80 dB at the listening position. Use C-Weighted Slow on the meter.

When I burned mine, I used 100 Hz as tone #1 and then 10 Hz as tone #2, etc.

The test tones pop/thump between notes; this is normal and another reason not to push them too hard.

If you are not interested in say 10-18 Hz, just skip it. It will save time and be easier on the woofer. Only the best subs will give useable output in that region anyway.

 

[Chris Grillo]

Ed Thanks,

I't will be interesting to see what my Boston VR500 will do!
My wife has to work friday so if i can get the kids to not bother me for about 30min I will chart it and if I can figure up how to post the results I will!! Thanks to all!!
This is starting to be fun!!!

 

[Chris Xolotl]

Thanks steve_nn for the corrected SPL post.

I ran the test tones and heard the "pops" between the tracks. Didn't like that much. I'll see if there is a way to fix that. Maybe run all the tones together as one track.

 

[Chris Grillo]

Well I plotted both my sub and my mains and put them on one chart but I don't know how to post the jpg!!HELP!
Also I was hoping you guys could recommend a the right crossover point (from the charted info) until I get my SVS

 

[WayneO]

Well I went and did the chart the way Ed recommended, 20-100hz in stock tune at 80db with 100hz tone. I used the test tone link and some of the tones didn't match up perfectly with the corrected RS meter values offered in the excel speadsheet, but I used the closest tone in that situation. I assume that wouldn't affect the graph results? Those tones were off like .1-2hz. Ran these from my DVD player via optical link with "stereo" mode selected on my receiver, front speaker cables removed, then reconnected for testing the sub and speakers together. Speakers set to "small", "large" gave the same numbers. But I wonder why the db's dropped so much once I read the mains with the sub. Does this seem wrong?

Well here it is, any comments or insight would be welcome, then it's on to the PB2+ when it gets here next week.

Values are "corrected":


.

Chris, you need someone to host your pics, if you don't have web space, you can email em and I'll host them for you. PM me if you need to

 

[Edward J M]

WayneO:

Try messing with the phase control of the 20-39PC+. You may be getting some negative interaction between the mains and the sub (even when the mains are set to small).

I found in my room that a 180 phase setting worked best (and I've owned both the 20-39PC+ and the PB2+).

You have a nice looking curve below 40 Hz and flat in-room extension to 20 Hz - nice.

Chris:

Yes, you need a website to host your pics (.jpg's). Looks like WayneO has you covered.

Ed